The 27 Brussels leaders are expected to adopt a negotiating mandate for the future trading relationship with Britain and sign off on a two-year transition, starting at the end of March next year.
Theresa May is flying into Brussels later today where she is expected to make a few words on the agreed transition deal.
But the leaders will meet without the PM on Friday where they are expected to give the green light to a two-year transition period following the progress made by negotiators over the weekend.
Russia is also set to dominate discussions following the nerve agent attack on former Russian spy Sergei Skripal and his daughter, Yulia, in Salisbury.
EU Summit live: Brexit is set to dominate the Brussels meeting
Mrs May is expected to urge Europe to stand united in the face of a “shared” and “long-term” threat.
The first session is a discussion trade, with US President Donald Trump’s steel tariffs high on the agenda.
Please follow Express.co.uk below for live updates on the EU Summit throughout the day…..
EU Summit live: Juncker has pledged his commitment to the Baltics
11:32am update: The EU has reinforced its committments to the Baltic region
Juncker met with the Lituanian President and prime minister’s of Latvia, Poland and Estonia where he pleged to end the electricity isolation of the Baltics.
11:26am update: EU Council President has received Bulgarian PM Boyko Borissov
EU Summit live: Donald Tusk receives the Bulgarian PM
11:19am update: Millionaire businessman Michael Bloomberg has described Brexit as the “dumbest thing a country has ever done”
During a keynote speech at the European Council Summit in Brussels, he said: “When I was in London a few months ago, I said Brexit was the dumbest thing any country had ever done, but I added, then we Trumped it.”
The audience burst into laughter and applause, with Mr Bloomberg even struggling to avoid laughing at his own quip.
EU Summit live: Dalia Grybauskaitė gives the thumbs up
10:55am update: Lithuania appears to be supporting the UK’s tough stance against Russia
President Dalia Grybauskaitė gave the thumbs up when she was asked if she would be supporting Theresa May’s firm stance against Moscow in response to the nerve agent attack against former Russian spy Sergei Skripal
EU Summit live: Juncker greets leaders of Lithuania, Poland, Estonia
10:22am: Juncker appears to BLAME German Chancellor Angela Merkel for his letter of congratulations to Putin
The EU chief told reporters: “I wrote the same letter than Mrs Merkel – ask Mrs Merkel if it was the right thing to do,” as he greeted the Lituanian President and prime minister’s of Latvia, Poland and Estonia.
Juncker has faced criticism over his letter in Brussels, with a liberal group in the European Parliament saying: “We do not think that Putin’s illiberal policies and election strategies deserve congratulations.”
A second, conservative faction called the letter “nauseating”.
EU summit live: Brussels have been reflecting on the terror attack in March 2016
10:14am: Brussels have been reflecting on the terror attack that killed 32 people on March 22, 2016
Brussels PM Charles Michel laid a wreath in memory of the victims
10:06am: Donald Tusk has held a meeting with Sweden
Swedish Prime Minister Stefan Lofven met with the European Council President ahead of the EU leaders summit
EU Summit live: Swedish PM Stefan Lofven meets Donald Tusk
9:31am: Desperate Emmanuel Macron meets with Dutch PM Mark Rutte
The French president is on a mission to gather support for his far-reaching EU reforms.
He met Mr Rutte at the Hague last night ahead of the EU Summit.
9:21am: EU members are not entirely united over its stance against Russia
Greece and Hungary are reportedy reluctant to support the UK to blame Russia entirely for the nerve agent attack against Sergei Skripal on British soil.
9:13am: Juncker faces a tough crowd after his congratulatory message to Putin
The EU boss raised eyebrows when he wished the Russian president “every sucess” following his presidential victory, with some calling his message “nauseating” and “an insult”.
EU Council President Donald Tusk told reporters: “After the Salisbury attack, I’m not in the mood to celebrate President Putin’s reappointment.”
While Guy Verhofstdadt tweeted: “This is no time for congratulations.”
9:09am update: PM Theresa May is expected to tow a tough line against Russia during her appearance in Brussels
The Tory leader is expected to say: “The challenge from Russia is one that will endure for years to come. As a European democracy the UK will stand shoulder to shoulder with the EU and with NATO to face these threats together,” as she rallies on EU members to unite.
9:07am update: May is flying into Brussels for the end of the EU Summit
The PM is expected to make a few words at the end of the working dinner.
A UK official told politics news site, Politico.co.uk: “You can expect the PM to welcome the progress that’s been made.
“I wouldn’t expect it to be a big long speech.”